European patent application no. EP 0 746 130 A1 of German priority describes a mobile telephone comprising:
a memory for storing telephone numbers corresponding to incoming calls that have failed, PA1 a selection device for permitting the user to select the numbers he wishes to call back and PA1 a sorting and comparing device for automatically classifying the selected numbers in a call-back list according to an order of priority determined by the call-back profile of the user of the mobile telephone.
The call-back list is thus constructed automatically as a function of objective criterions such as the call-back ratio calculated beforehand for each stored number, the number of call attempts originating from a same number, or also the value of a weight factor assigned by the user to his favorite numbers, these criterions defining the call-back profile of the user.
Such management of a call-back list raises the drawback of being based on statistical criterions while not taking into account the kind of the incoming calls and, more particularly, their urgent character which cannot be foreseen beforehand.
Moreover, as this call-back list contains all the numbers corresponding to incoming calls that have failed when it is full (the call-back list having of necessity a small size), certain subscriber numbers already stored are likely to be erased by the addition of new numbers.
On the other hand, the sorting and comparing operation is carried out after the user has selected numbers to be called back, there being a possibility that certain numbers have been lost even before they may have been selected and sorted. Indeed, if the telephone is the object of various call attempts from the side of the same subscriber, his number is stored in the memory as many times as the subscriber has made calls, which causes the risk of saturating the memory very rapidly.